Billionaire industrialists Charles and David Koch are reported to be "exploring a bid" to acquire eight regional newspapers in the United States, including the Los Angeles Times, Chicago Tribune and Baltimore Sun.

Having emerged from bankruptcy at the end of last year, Tribune is hoping to sell off all its print assets, which have been valued at about $623m (£409m). That wouldn't be much of a stretch for Koch Industries - the energy and manufacturing conglomerate has annual revenues of about $115bn (£75bn).

The Koch brothers are regarded as ultra-conservative libertarians who believe "the conservative voice" in the States is "not being well represented."

But there are other possible bidders for all or part of Tribune's papers. And several are interested only in the LA Times, including Rupert Murdoch's News Corp and the billionaire Democratic donors, Eli Broad and Ronald W. Burkle.